I installed it on my linux box at work and it seems to work as well as the windows version. It would do for navigation in a pinch but getting directions from one address to another works for some addresses and not for others. It would definitely be a cool add-on to a real nav app especially using the $20 version that can read from a GPS. Depending on where you live it would be pretty much useless unless you like animated flyovers of blurry 1km resolution photos

the real thing is OpenStreetMap - it's gonna take a while to collect the data (except for the U.S, where the TIGER-import is running at about 1.000.000Nodes/day) but in the end it's the most viable solution for linux navigation.
right now on the software end gpsdrive is probably the best thing available. if you're using the CVS version you can import OpenStreetMap data.

I'm myself an OSM-addict, and mapping is a lot of fun + in the end (which is some years from now) data will probably be more exact/timely than commercial solutions.

i'd find it real cool, if in SW2 you could choose your nav.app of choice and have it switch to it (so everybody get's his preferred app)

Hello!
Google Earth is also one of my possible choices for navigation. Works flawlessly on my Debian Etch desktop. I am almost sure, you cannot use it for address to address planning, also there is not any street names.
But Google have some other project - Google Maps (completely online) with street names even of my little town at the edge of the world (be sure not to fall off ) in Eastern Europe. There is also a possibility to overlay sat image and navigation maps. And there comes a problem - they are not alligned, an error of approximately 50-70 meters. Not good in a city.
Another problem there is as it is online service you have to manually cache all maps and reuse them somehow.
And last but not least - legal stuff. As I understand - you may use this service, but are not allowed to change the maps or distribute. So, not good for an Open source project I am searching for. But maybe somebody have tried to do something with it. Could be good as it is global, not only US or Western Europe.